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168 MR. W. A. FORBES ON THE GENUS LATHAMUS. [Feb. 18, results of my inquiries before the Society to-night, in order to establish the view that Lathamus must be removed from the brush-tongued Trichoglossinee, with which it has been so generally asso­ciated, and must be considered a (no doubt aberrant) member of the Platycercine group. The pterylosis of this form having first struck my attention, I will describe this in the first instance, the more so as, as far as I know, no description of this part of the structure of the bird in question has yet been published. I may perhaps anticipate part of my paper on the pterylosis of the Psittaci in general, and point out briefly the general characters of the distribution of the feathering in these birds, so as to enable the reader without any further trouble to appreciate the points of distinction in this respect between Lathamus and the other species with which I have compared it. As will be evident from the figures (PI. XVT. figs. 1-6), the tracts of contour-feathers in a Parrot may be arranged as follows :- On the upper surface of the body, continuous in front with the feathering of the top and sides of the head, is a long narrow tract, the " superior tract," which divides behind in the interscapular region in a fork-like manner, forming the "scapular fork." Behind this, occupying the hinder part of the back and pelvis, is another, more or less Y-shaped tract, with the "handle " (which is usually short) of the fork placed close to the posterior extremity of the trunk, whilst the more lengthy "arms" of the Y are more anterior, and run in, in front, between the corresponding ones of the " scapular fork," usually becoming very feebly feathered in so doing. This tract may be called the " dorso-lumbar" fork. Scattered more irregularly and diffusely over the sides of the pelvis, and external to the last-named tract, is the " lumbar feathering," which passes posteriorly on each side into the narrower but more distinct" femoral tracts." These are continued onto the legs as far as the tarsi as the " crural tracts," clothing the legs in a trouser-like way. On the inferior surface, on each side, is a continuous tract, running from the upper part of the neck (where it may or may not unite with its fellow of the opposite side), over the breast and abdomen, to the anus. This " inferior tract," besides one or two small branches running towards the humerus and patagium (the first and second "humeral tracts"), gives off, at about the commencement of the sternum, a more or less separate and well-marked external branch, the " outer pectoral" tract, which runs down more or less parallel to the main part of the inferior tract for a little way, but ceases before the thighs. Amongst the various species of Psittaci I have examined, well-marked differences in some of these tracts occur, more particularly in the arrangement of the "dorso-lumbar fork," and the greater or lesser development of a distinct "outer pectoral" branch to the inferior tract. In Lathamus discolor (PI. XVI. figs. 1, 2), the inferior tract of each side starts from about the angle of the jaw, and does not unite with its fellow. On the sternum it is about eight or nine feathers broad at